Mattress covers are well known in the art. One of the most common mattress covers utilizes sections of nonstretchable fabric which are stitched together to form a top platform and a skirt which descends from the platform. An elastic band stitched to the bottom edge of the skirt aids in conforming the mattress cove to the mattress. Although this type of mattress cover is relatively inexpensive, it has at least one disadvantage: the skirt cannot expand to mattresses with varying thicknesses.
In recent years, manufacturers have increased the thickness or depth of mattresses, while maintaining the same length and width. Thus, if a consumer replaces one queen-sized mattress with another, the new mattress may have considerably more depth than the previous mattress, even though it is also queen-sized. As a result, the consumer's previous mattress cover may not fit the new mattress.
In an effort to solve this problem, manufacturers have attempted to manufacture adjustable mattress covers. For example, one supplier of mattress covers combined fabrics with different amounts of stretchability to construct an adjustable mattress cover with stretch in the XD or cross direction, e.g. along the width of the fabric. Although this design appeared to solve the increased mattress depth problem, it was relatively expensive to produce.
U.S. Pat. No. 4,985,953 assigned to Louisville Bedding Co. described an attempt to solve the mattress depth problem using a two-step method. A basic skirt fabric was woven and elastic cords were then stitched into the woven fabric to create gathers in the skirt. A top platform and a bottom elastic band were then attached to the skirt. The resulting mattress cover was adjustable due to the stretch in the XD direction of the skirt fabric.
Although the prior art adjustable mattress covers apparently adjusted to mattresses of different thicknesses, such presently available covers have at least one undesirable side effect: unnecessary bulk. For example, when a mattress cover designed to adjust to mattresses with thicknesses ranging from 7" to 14" is placed on a 7" thick mattress, there is a large amount of extra fabric in the skirt which must be handled. The prior art mattress covers generally deal with the bulkiness problem by tucking the extra fabric underneath the mattress. This creates an uneven appearance on the mattress and makes the cover difficult to put in place.
In addition, the prior art adjustable mattress covers do not fit the upper surface and four corners of the mattress very well due to the manufacturing process. No tension is placed on the skirt fabric in the MD on longitudinal direction e.g. along the length of the skirt, prior to the skirt's attachment to the top platform. As a result, the mattress cover may not conform smoothly to the sides, corners and top of the mattress, and creates wrinkles in the mattress cover and in sheets place over the mattress cover.
Another problem associated with prior art adjustable mattress covers is attaching the elastic band to a skirt having greater elasticity. Usually, a skirt is stitched to an elastic band in its relaxed, unstretched position. When the finished mattress cover is subsequently placed on a mattress, the thread used to attach the elastic band and the skirt breaks due to the greater amount of stretch in the skirt relative to the thread. When the thread breaks, the elastic band disengages from the skirt, and ceases to conform the mattress cover to the mattress.